Avian Influenza in Companion Animals

April 28, 2015

Q:Is it true that cats can get avian influenza?

A: A U.S. Geological Survey chart illustrates animal species that have been found to be affected by a specific strain of avian influenza (Guangdong lineage H5N1). Additionally, a 2012 article by the CDC suggests that cats are indeed at risk of disease and/or death from HPAI, while other studies (such as an article published by the CDC in 2007) shown that cats can sometimes be infected subclinically. Domestic cats also are believed to play a role in the epidemiology of HPAI in both people and animals. In August 2006, a confirmed case of H5N1 HPAI infection in a domestic cat in Iraq was reported in Emerging Infectious Diseases.2 Prior to these cases, there had been unconfirmed reports of H5N1 HPAI infection in domestic cats in Southeast Asia.

Clinical signs in infected cats have not been extensively described, but include fever, listlessness, conjunctivitis, difficulty breathing, and death. These signs are commonly encountered in other respiratory disease syndromes of cats, so laboratory confirmation of highly pathogenic avian influenza virus infection is necessary for a definitive diagnosis.

Q:What is the incubation period of highly pathogenic avian influenza virus in cats?

A: In experimentally infected cats, signs were seen as early as 2 days after inoculation. In a single report describing a naturally infected cat, signs were observed 5 days after the cat ate the carcass of an infected pigeon.

Q:How do cats become infected? Can they spread the virus?

A: Natural highly pathogenic avian influenza (HPAI) infections in domestic cats appear to be associated with outbreaks in domestic or wild birds and acquired through ingestion of raw meat likely infected with the HPAI virus, although respiratory communicability also appears to be a route of transmission. Experimentally infected cats have been found to transmit the virus to other cats in close contact. Fortunately, there is no evidence to date that domestic cats play a sustained role in the natural transmission cycle of HPAI viruses. There have been no known cases of human avian influenza (AI) resulting from exposure to sick cats, and there have been no outbreaks of AI among domestic cat populations. Additionally, naturally infected cats appear to shed the virus sporadically and for less than two weeks.

Q:How is the virus shed by companion animals?

A: In experimentally infected cats, the virus was detected by swabbing nasal, pharyngeal (throat), and rectal tissues. "Shedding," as it applies to viruses, means that the animal's secretions and/or feces contain viral particles that may infect other animals or people. Scientists believe the virus is shed in oral and respiratory secretions and feces from naturally infected cats. Evidence suggests that the highly pathogenic avian influenza (HPAI) virus is not shed in the same quantities from cats as it is from birds, and that the risk posed to humans by infected cats is low.

Q:What is the current risk that a cat will become infected with highly pathogenic avian influenza in the United States?

A: Although highly pathogenic avian influenza (HPAI) has circulated in Asia, Africa, and Europe, they differ from strains that have been identified in the United States. The risk of a cat contracting the disease in this country is still currently considered very low.

Helpful precautionary measures include keeping domestic cats indoors to prevent exposure to potentially infected birds when HPAI is detected in the area, avoiding contact with wild birds and other animals outside the home that could potentially be infected, and avoiding feeding poultry or other bird products that may be infected with HPAI to cats. Owners of ill cats, particularly those known or suspected to have been exposed to sick or dead birds, are encouraged to have their cats examined by a veterinarian.

Q:My cat ate a dead bird (or was found with a dead bird in its mouth). What do I do?

A: Contact your veterinarian for assistance. The international Food and Agriculture Organization has indicated that transmission of avian influenza to a cat from a dead bird is extremely low. However, depending on the area where you live (and whether HPAI has been identified in that geographic region) as well as guidance developed by state and federal authorities, he or she may recommend that you confine the cat indoors in a separate room or cage away from humans and other animals for 7 to 10 days and avoid being scratched or bitten. If the cat remains healthy throughout this time, your cat probably poses a minimal risk of infection to other animals and people.

If your cat develops signs of disease consistent with AI infection, your veterinarian should be notified immediately and the cat should continue to be confined to minimize its contact with people and other animals. Wear disposable gloves and disinfect all surfaces the cat may have contacted, including food and water dishes and litter boxes. Wash your hands thoroughly after disinfecting surfaces and equipment and after handling potentially exposed cats.

A: If the subtypes of HPAI detected in the USA is found to infect species of small animals that cats would likely eat or prey upon (e.g., mice, small species of birds), then free-roaming and feral cats might be at risk of infection. However, in areas of Europe where large numbers of wild birds were found to be infected, only a very small number of cats potentially exposed to the virus became infected themselves.

Although the risk to caretakers of feral cat colonies would likely be quite low, the following precautions should be taken:

Minimize direct contact with feral cats.

Avoid being scratched or bitten.

Wear disposable gloves when handling food and water dishes, cages, and other surfaces that cats may have contacted, and wash hands afterwards.

Regularly clean and disinfect food and water dishes and cages.

Consult with your veterinarian if you have any additional questions or concerns.

Note that the CDC Advisory Committee on Immunization Practices (ACIP) recommends that everyone 6 months and older be vaccinated annually against seasonal influenza.

Q:Can dogs become infected with avian influenza?

A: Like cats, dogs are not usually susceptible to avian influenza (AI) viruses; however, one study found that dogs experimentally infected with Guangdong lineage H5N1 HPAI were susceptible. In this study, all dogs were found to have replicating virus. Also, an unpublished study carried out in 2005 by the National Institute of Animal Health in Bangkok indicated that dogs could be infected with the virus. No clinical disease was detected in association with that infection. This limited information is insufficient to determine exactly how susceptible dogs are to the virus.

In October 2006, a case of fatal infection of a dog with the N5N1 AI virus was described in Emerging Infectious Diseases.1 The dog became infected after eating the carcass of an infected duck during the second wave of H5N1 highly pathogenic avian influenza (HPAI) outbreaks in Thailand in October 2004. Approximately 5 days after eating the duck, the dog was febrile, panting, and lethargic; it died six days after eating the duck. Necropsy revealed severe congestion and fluid accumulation in the lungs, and congestion of the spleen, kidneys, and liver. View the report on the CDC Web site.

Q:What are the clinical signs of highly pathogenic avian influenza in dogs?

A: HPAI of the Guangdong H5N1 lineage , in dogs. have been reported to occur occasionally, with signs including fever, panting, and lethargy in one case report. Signs reported in another experiment include conjunctivitis, dyspnea, and anorexia. Information on other HPAI strains is lacking.

Q:How do dogs become infected? Can they spread the virus?

A: There is not enough information available about highly pathogenic avian influenza (HPAI) infections in dogs to know how infection would develop. Domestic cats in Europe appear to have become infected by eating infected poultry or wild birds. Details concerning a case of Guangdong lineage H5N1 infection in a dog in October 2004 were recently published; the dog was infected after it ate the carcass of an infected duck. View the report on the CDC Web site. View the report on the CDC Web site.

Q:What is the current risk that a dog will become infected with highly pathogenic avian influenza virus in the United States?

A: At the moment, there is little risk of a dog in the United States becoming infected with highly pathogenic avian influenza even though subtypes that have circulated in Asia, Europe, and Africa have been found in the United States.

A: Poultry products are only a risk if they come from infected birds and are eaten while raw (unprocessed). It may be possible for cats and dogs to contract highly pathogenic avian influenza (HPAI) by eating infected raw poultry products or infected products from other bird species.

A:If your cat, and potentially your dog, consumed raw meat from an infected bird, it may be possible for them to become infected with highly pathogenic avian influenza (HPAI). However, due to safeguards established by governmental agencies to detect HPAI early in poultry and wild birds, it is very unlikely that infected poultry meat would ever reach the marketplace. The risk, therefore, of a pet becoming infected by eating uncooked poultry is extremely low. Nevertheless, for a variety of reasons, feeding raw meat to pets is not recommended. The AVMA asserts that cats and dogs may develop foodborne illness after being fed animal-source protein contaminated with these organisms if adequate steps are not taken to eliminate pathogens; secondary transmission of these pathogens to humans (e.g., pet owners) has also been reported.

Q:Can companion birds be infected with highly pathogenic avian influenza virus? What are the clinical signs in companion birds?

A: Information on the susceptibility of all avian species with avian influenza are not available, however, the risk can be minimized by avoiding contact with wild birds. Even though HPAI has been detected in the United States, indoor birds continue to have a very low risk of becoming infected. Birds housed outdoors, however, should be protected from contact with wild migratory birds (especially waterfowl and shorebirds), their droppings, and water frequented by waterfowl and shorebirds. If infected, it may be possible for companion birds to spread the virus.

If affected, companion birds may show signs of respiratory (e.g., discharge from the nose and/or eyes, sneezing, ruffled feathers, or labored breathing), gastrointestinal (e.g., diarrhea), and/or neurologic (e.g., incoordination, depression) disease and be lethargic. There are no clinical signs that are unique to AI infection in companion birds, and some infected birds may show no signs of illness.

Q:What is the risk that my bird will become infected with highly pathogenic avian influenza virus? Can it spread the virus if it becomes infected?

A: Indoor birds are at very low risk of becoming infected. Should HPAI be detected in the area, birds housed outdoors should be protected from contact with wild migratory birds (especially waterfowl and shorebirds), their droppings, and water frequented by waterfowl and shorebirds. If companion birds or backyard poultry become infected, it may be possible for them to spread the virus. See USDA’s Avian Influenza and Biosecurity for the Birds resources for additional tips on keeping your birds protected.

Q:Is there a vaccine available to protect companion animals against highly pathogenic avian influenza virus?

A: Currently, there is no USDA-licensed vaccine against highly pathogenic avian influenza infection available for use in companion animals in the United States.

Q:There are wild birds outside—can I let my dog/cat out?

A: Risk of HPAI infection in a dog is very low. Keeping cats and dogs indoors, unless being walked on a leash or otherwise confined, is best for their safety, regardless of risk of infection with the virus. Cats and dogs allowed to roam outdoors are exposed to many dangers, including automobile injuries, animal bites, poisoning, and other infectious diseases.

Q:Can my pet catch "bird flu" if it's not a bird?

A: In addition to wild and domestic birds and poultry, humans, domestic cats, and dogs, we know that pigs, palm civets, cynomolgus macaques, New Zealand white rabbits, stone martens, tigers, leopards, ferrets and rats can become infected with the Guangdong lineage of H5N1 highly pathogenic avian influenza (HPAI) virus. But the risk with the current strains in the U.S. is unknown. It's possible that other mammals may also be susceptible to HPAI.

Q:Can I give highly pathogenic avian influenza virus to my animal?

A: Transmission of influenza viruses depends on exposure to the virus and adaptation by the virus to the new host. Transmission of highly pathogenic avian influenza (HPAI) virus from humans to animals (including cats, dogs, and birds) has not been documented, but may be theoretically possible under certain circumstances. Because HPAI can cause illness and death in humans, the health of the pet owner and their potential to transmit the virus to other humans is the primary concern for public health officials, including veterinarians.

A: Certain mammalian species are known to be susceptible to infection with the highly pathogenic avian influenza (HPAI) virus, including pigs. Pot-bellied pigs are not considered to be reservoirs for the virus and should not spread HPAI. However, infection control precautions similar to those recommended for other companion animal species should be followed.